Urumqi, China (CNN) -- Urumqi, the capital of China's far-western Xinjiang Province, was calm but definitely tense Friday, four years after violent clashes left hundreds dead and exposed deep ethnic rifts in the region. In the days leading up to the anniversary, and in the wake of recent attacks that left 35 dead in Xinjiang, Chinese authorities have taken measures to thwart further unrest. Paramilitary police in camouflaged fatigues with automatic weapons and riot gear have been stationed outside key points throughout the capital, including government buildings, banks and major intersections. While it is not unusual for there to be a visible police presence in a city known for past troubles, the number of armed troops on the streets has increased dramatically -- one main street next to a local theater in the city was backed up with a column of police trucks, armored personnel carriers and other riot-control vehicles.

Uyghurs and
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Han Chinese generally frequent different shops, live in different neighborhoods and go to different schools.


Video gamers spend tons of time -- for many it's 10,000 hours by age 21 -- battling mythic monsters, shooting aliens and rescuing princesses from digital castles. Adrien Treuille wants to put those efforts to better use. The Carnegie Mellon computer scientist is the creator of two online games -- Foldit and EteRNA -- that put video gamers to work solving epic scientific puzzles. His aim is to make super-boring-sounding scientific mysteries like "protein folding" and "RNA synthesis" fun and challenging for gamers. The results have been staggering, as Foldit and EteRNA players -- there are about 430,000 of them between those two games, most of them playing Foldit -- continue to make discoveries that had eluded  scientists and their supercomputers.

Earlier this month, for example,
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Foldit players helped solve a puzzle about proteins that could further research into HIV/AIDS.


(CNN) -- Last week, The New York Times gave us an inside look at what it's like to work at Foxconn, the manufacturing company that owns several China-based factories that crank out Apple's iPads, iPhones and iPods by the millions. The story is full of examples of horrifying working conditions in Foxconn's factories that would never fly here in the United States. Here are some of the more troubling ones from the Times story: Foxconn is a 24-hour operation. Employees work six days a week, sometimes in 12-hour shifts. They're on their feet for so long that their legs begin to swell. There are underage workers. They live in crowded dorms on the factory's campus. In recent years, there have been reports of workers leaping from buildings in apparent suicides.

When it comes to smartphones and tablets,
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Apple still makes the best there are.